Specific Aim 1: To perform a prospective, randomized, placebo-controlled trial to evaluate efficacy of intracoronary autologous bone marrow-derived angioblasts on native heart function in LVAD recipients awaiting cardiac transplantation. Secondary end-points include measurement of neovascularization and cardiac regeneration in explanted native hearts, and determining whether a correlation exists between age and reduced numbers of mobilized bone marrow stem cells. Specific Aim 2: To identify the influence of adult bone marrow-derived angioblasts on mesenchymal stem cell migration, survival, proliferation and differentiation in vitro. Specific Aim 3: To determine if co-transplantation of angioblasts together with autologous mesenchymal stem cells enhances engraftment, myogenesis, and cardiac function in vivo after acute myocardial ischemia.